docs: def unpack(self, unpacker):
          """
          Unpack an attributes table from an unpacker stream.  Modifies the
          structure of this instance.
          """
  
          # bound method for dereferencing constants
          cval = self.cpool.deref_const
  
          (count,) = unpacker.unpack_struct(_H)
          for _i in range(0, count):
              (name, size) = unpacker.unpack_struct(_HI)
              self[cval(name)] = unpacker.read(size)